It is known to control various unwanted pollutants that are emitted from the compression ignition diesel engine by use of injecting or fogging the intake air stream of such engines with a mixture of ethanol, water and other substances. Such a system is typically installed as additional equipment to the pre-existing diesel injection system and does not replace the diesel fuel system. Intake air fogging with an ethanol solution reduces the combustion temperature while adding new chemical reactions, thereby reducing Nitrogen Oxides (NOX) and particulate matter rates.
Example non-limiting technology herein addresses the formulation and control of the electrical pulses that are used to turn on and pulse the injector(s), which disperse the ethanol additive solution, and to improved systems and methods that provide automatic injection of additives including but not limited to ethanol and the like into an internal combustion engine to reduce pollutants and for other purposes.
FIG. 1 shows an example conventional ethanol additive system of the general type in which the exemplary illustrative non-limiting technology herein can be used. In the particular non-limiting example shown, electronic control module 1 is powered up by connection to the vehicle battery 2, through the key switch 3, and fuse 4. The common ground connection 5 completes the module's power circuit.
A method to detect and synchronize to the engine's crankshaft is installed on the crankshaft consisting of rotating indices 6, consisting of teeth or magnets, which is equal or greater in number to at least the number of cylinders divided by 2. A sensor of either magnetic reluctance or Hall-effect type 7, then delivers a pulse corresponding to the passing of each indicia. Sensor 7 is then wired to module 1.
Another sensor 8, which varies in internal resistance as a function of tip temperature is installed in or near the engine's coolant jacket. This temperature sensor 8, is wired to the module 1, and thereby allows the modules software to determine the temperature of the engine's coolant.
Another sensor 9, is connected by way of tubes or fittings to the engines intake manifold. This sensor varies in output voltage or resistance as a function of the pressure of the intake manifold. This sensor 9, is wired to the module 1, and allows the software to determine the intake manifold or turbo pressure of the engine.
Another sensor 10, is inserted into the ethanol solution tank or pressure line and it determines the presence of an adequate amount of ethanol solution. This sensor is wired to the control module 1 and allows the software to determine if adequate ethanol is available for the system to operate properly.
A malfunction indicator lamp 11, is also connected to the module 1. It shall inform the engine operator that the system is operating correctly or may turn on or flash to indicate trouble such as failed sensors, empty ethanol tank, or other malfunctions.
Should the proper conditions exist of engine rotating determined by sensor 7, warm engine coolant per sensor 8 and adequate additive determined by sensor 10, the module 1, shall activate relay 12, thereby powering on the additive fuel pump 13 and applying power to the fuel injectors 15.
Should a pressure switch be used for #10, a delay may be involved between turning relay 12 on and determining if sufficient pressure is present before injection is started or malfunction is indicated.
Once the proper conditions for additive injection is met, the module 1, reads the intake manifold sensor 9 and the engine RPM via the time pulse spacing of sensor 7 and uses a 3 dimensional “look up and linear interpolation” table to determine the injector pulse width. The module 1 has low side transistor switches 15A to 15D, that turn on injectors 16A to 16D, for an experimentally determined amount of time period. The start of the injector pulse corresponds to the time point(s) at which pulse voltage transitions occur from crankshaft sensor 7. In this way the injector pulse starting points are synchronized to specific angular positions of the crankshaft.
FIG. 2 shows an example non-limiting timing relationship between the crankshaft sensor voltage waveform 20, and the outputs 21 to 24. The control module's microcomputer detects a voltage transition of waveform 20, in this case the falling edge 21b. The output voltage waveform of circuit 15a is 21a. When falling edge 21b occurs, a timer channel in the microcomputer is turned on and the injector begins to inject the additive solution. The timer proceeds to time out period 21c. 
When the timer completes its time count, the injector output turns off. This cycle is repeated on successive crankshaft sensor voltages 22b, 23b and 24b falling edges thereby producing a sequential injection cycle of other waveforms 22a, 23a and 24a as shown in FIG. 2.
In one example non-limiting implementation, the injector period is determined by a 3 dimensional map. The microcomputer code uses a grid of RPM and manifold sensor (MAP) values in combination with linear interpolation and extrapolation routines to determine the current pulse width. FIG. 3 shows a graphical representation of the relationship between the rotational speed of crankshaft 6 (in RPM) the signal from the manifold pressure sensor (MAP) 9 and the periods of injector pulse widths 15a-d. 
In one example non-limiting implementation, a determination and subsequent calibration of the injector pulse width grid points is devised and inputted by use of a PC type or other computer 17, which allows the user to alter the injector pulse width and then save the changes regarding coolant temperature, intake manifold pressure 3D points, engine RPM points 3D points, injector pulse widths and other required setup values.
While such conventional ethanol additive systems provide useful functionality, further improvements are possible and desirable. In particular, installing a system of the type shown in FIG. 1 can be expensive due to the many interconnects, sensors and components.
One example non-limiting implementation of the technology herein provides a microcomputer equipped electronic control module that has the necessary circuits to capture data that is available on the industry standard serial communications bus which was adopted by most diesel engine manufactures after 1998. This bus is commonly called “J1939”, and refers to the Society of Automotive Engineers (SAE) practices specifications J1939. The example non-limiting technology herein uses this data and software algorithms to eliminate cost and labor of adding additional sensors, which are typically needed to obtain the necessary data to produce the desired result.
The example non-limiting technology herein thus provides a system for the delivery of ethanol or other solution additives to the intake manifold of compression ignition diesel engines. The system may comprise an electronic control module containing a microcomputer capable of monitoring SAE J1939 serial data, receive a signal from an additive monitoring sensor and have outputs to turn on a pump relay, indicator lamp and from 1 to n pulse width modulated electrical fluid injectors. Such a system can retrieve various data parameters from the J1939 data stream such as engine RPM, Engine load, coolant temperature and other data. Such a system can determine if the proper level of additive is present and when the proper engine operating conditions are met, can turn on a fluid pump electrical relay. Such a system can calculate with linear interpolation and extrapolation software routines from data stored in a 3 dimensional array a desired injector pulse width. Such a system does not need to use a crankshaft sensor or other direct means to measure engine speed or crankshaft position and instead is using data from the J1939 data bus. Such a system does not use a pressure sensor or other direct means to measure engine load or fuel rate and instead is using data from the J1939 data bus. Such a system can create a start of injection pulse instants which are not exactly synchronized to the exact position of the crankshaft but occur at a rate of injection which is approximately proportional to the speed of crankshaft rotation and such injection rate is constantly adjusted to the most recently available RPM value as obtained from the J1939 data. Such a system has the ability to allow arbitrary injector output pattern firing-orders by use of a programmable table. Such a system can monitor the additive fluid level or pressure and turn on a diagnostic lamp or notify the operator in another way if the system operation is not within prescribed parameters. Such a system uses a data communications interface to a PC type computer and a graphical human interface to allow for modifications to stored calibration parameters and to see current operating conditions within the system.